Development of a Population-Level Dichotomous Indicator of Minimum Dietary Diversity as a Proxy for Micronutrient Adequacy in Adolescents Aged 10-19 Y in the United States.

Background: Diversity is a key component of diet quality and health, but no indicator exists for adolescents under the age of 15 y.

Objectives: To establish a dichotomous indicator for population-level assessment of adolescent dietary diversity as a proxy for micronutrient adequacy.

Methods: We used the probability approach to construct mean probability of adequacy (MPA) of 11 micronutrients from 2 d of 24-h dietary recall data from NHANES, 2007-2018. For each micronutrient, probability of adequacy (PA) was calculated using the best linear unbiased predictor of usual intake. Adolescent dietary diversity score (ADDS) was derived with a maximum score of 10 food groups. Generalized linear mixed models were used to examine associations between ADDS and MPA. Receiver operating characteristic analysis was used to establish a cutoff for minimum dietary diversity for adolescents (MDD-A) using an energy-adjusted logistic model with ADDS predicting MPA > 0.6.

Results: PA was >80% for all nutrients except vitamin C (42.1%), folate (65.7%), and calcium (23.8%). Population MPA was 79.4%, and nearly 92% of adolescents had an MPA > 0.6. ADDS was positively associated with MPA, and energy was a significant confounder. The area under the curve was >0.8 on both days with sensitivity and specificity ranging from 0.71 to 0.80. The MDD-A cutoff was calculated as 5.12 and 5.10 food groups on days 1 and 2, respectively.

Conclusions: In U.S. adolescents, the best cutoff for a dichotomous indicator of dietary diversity as a proxy for micronutrient adequacy is 6 food groups in a given day. Future research could validate MDD-A and its associated cutoff for use across country contexts.